1. Field of the Invention
The present invention relates to a manufacturing method of an absorbent article in which multiple elastic members are arranged on a predetermined curved line.
2. Description of the Related Art
Conventionally, a manufacturing method of an absorbent article including the following steps has been known.
Firstly, an elastic member bundle is fed in a conveyance direction (Machine Direction (MD)) via a line splitter, and is thereby split into multiple elastic members.
Secondly, an adhesive is applied at least on a predetermined curved line on a web continuously conveyed.
Thirdly, the multiple elastic members thus split are placed on the web while being swung in a direction (Crossing Direction (CD)) which crosses the conveyance direction.
With the steps, the multiple elastic members can be arranged on the predetermined curved line in a crotch region of the absorbent article.
Here, the elastic member bundle formed by splitting a single original elastic member into multiple elastic members with a slit, and bundling and pressurizing the multiple elastic members is used as the above-described elastic member bundle (for example, see Japanese Patent Application Publication No. H 6-70958 and Japanese Patent No. 3679966).
However, the conventional manufacturing method of an absorbent article has not specifically defined any specification for the elastic member bundle used in the above-described steps, except quality of material and dimensions of each elastic member.
In the above-described steps, since it is required to swing the split multiple elastic members in the CD, a torsion stress acts on an elastic member bundle before being split at a line splitter. This has caused a problem that the elastic member bundle cannot be split into the multiple elastic members properly and the elastic member bundle can be broken easily.
Further, suppose that an autohesive raw material, such as crude rubber, is used as a material (elastic member) to be arranged in the crotch region of the absorbent article. In this case, since it is difficult to make rolls from the material, the material is fed from inside a box in which the material is housed by dropping it down the box. Here, when the material is dropped down into the box thread by thread, the threads can easily tangle with each other in the box since each thread is too thin (about 1 to 2 mm). This tangle can lead to a problem that the thread might be broken during feeding.
As a result, a manufacturing line has to be stopped for installing a new elastic member bundle again, thus resulting in a problem of causing a decrease in production reliability and yield.
Therefore, the present invention has been made in view of the above-described problems, and an object thereof is to provide a manufacturing method of an absorbent article capable of solving the problem that an elastic member bundle can be broken easily at a line splitter, by using an elastic member bundle having line-splitting strength measured by a predetermined measuring method within a predetermined range.